A suicide car bomb attack targeting a passenger bus carrying Shiite pilgrims killed two people and wounded at least 17 in southwest Pakistan on Wednesday, officials said.
The attack took place in Akhtarabad, on the outskirts of Quetta, the capital of Baluchistan province which borders Iran and Afghanistan.
"An explosive laden car which was parked along the roadside blew up as the bus passed by it, killing two people and wounding 17 people," Quetta city police chief Abdul Razzaq Cheema told AFP.
He said that the 17 injured included four policemen.
Police officials who had been escorting the bus rescued passengers from the wreckage before it caught fire, Cheema added.
He said the bus was bringing back at least 46 pilgrims to Quetta from Iran.
Senior local police official Muhammad Jaffer also confirmed the incident and casualties.
Local bomb disposal chief Commander Razzaq, known by one name, told AFP that the car had been blown up by somebody sitting in it.
Nobody has so far claimed responsibility for the attack but there has been a rise in sectarian violence in Pakistan after several deadly clashes between Sunni and Shiite Muslim groups near Islamabad in November last year.
Shiites make up around 20 percent of Pakistan's population, which is largely Sunni Muslim.
Oil and gas-rich Baluchistan has been badly hit by a decade-long Baluch separatist insurgency and sectarian violence, mainly targeting Shiite Muslims from the Hazara ethnic community.
Baluch rebels have also been fighting since 2004 for political autonomy and a greater share of profits from the region's natural oil, gas and mineral resources.
Two huge bomb attacks in Quetta in January and February last year targeting Shiites from the Hazara ethnic community killed nearly 200 people.